1. Speed, Time and Distance Speed = Distance/Time, Time = Distance/Speed, Distance = (Speed x Time)
2. km/h to m/s Conversion: a km/hr = (a x 5/18)m/s
3. m/s to km/h Conversion a m/s =(a x 18/5)km/hr
4. If the ratio of the speeds of A and B is a : b, then the ratio of the time taken by them to cover the same distance is 1/a : 1/b or b : a 5. Suppose a man covers a certain distance at x km/h and an equal distance at y km/h. Then, the average speed during the whole journey is (2xy / (x +y)) km/h.